Self-releasing fishing rod tool



Sept. 15, 1953 'T. M. HUNT ET AL 2,652,281 SELF-RELEASING FISHING ROD TOOL Filed Oct. 2, 1950 2 Sheets-She et l INVENTORS 5' IMF-fun Z TLNz' c 720 Z5 BY QM ATTORNEYS Sept. 15, 1953 T. M. HUNT ETAL SELF-RELEASING FISHING ROD TOOL 2 Sheets -Sheet 2 Filed 001;. 2, 1950 INVENTORS QLM ATTORNEYS Patented Sept. 15, 1953 2,652,281 SELF-RELEASING FISHING ROD TOOL Theodore M. Hunt and Troy Lee Nichols, Tulsa,

Okla.; said Hunt assignor to said Nichols Application October 2, 1950, Serial No. 187,982

1 Claim.

This invention relates to a fishing tool for drill rods.

An object of this invention is to provide a tool for pulling drill rods from wells which will automatically grip the drill rod, and in the event the drill rod is not caught onto an obstruction the drill rod may be readily pulled from the well.

The invention also includes means whereby the fishing tool may be automatically released from the drill rod if the latter is stuck in the well so that the fishing tool may be removed without the rod.

Another object of this invention is to provide a fishing tool embodying a rod and a casing secured to the lower end of the rod by means of a shear pin which is not under any strain when the rod is capable of being pulled.

With the above and other objects in view, my invention consists in the arrangement, combination and details of construction disclosed in the drawings and specification, and then more particularly pointed out in the appended claim.

In the drawings:

Figure 1 is a vertical section partly broken away and in detail of a fishing tool or a drill rod constructed according to an embodiment of this invention showing the tool in rod gripping position with the shear pin broken.

Figure 2 is a vertical sectional view showing the tool in rod releasing position.

Figure 3 is a fragmentary sectional view taken on the line 3 3 of Figure 2.

Figure 4 is a fragmentary sectional view taken on the line 4-4 of Figure ,2.

Figure 5 is a fragmentary sectional view taken on the line 5-5 of Figure 1.

Figure 6 is a sectional view taken on the line 6-6 of Figure 2.

Figure 7 is a sectional view taken on the line l-1 of Figure 2.

Figure 8 is a fragmentary vertical section showing the tool in rod gripping position.

Referring to the drawings, the numeral I designates generally an elongated tubular or cylindrical casing which has threaded into the upper end thereof a plug II. The plug II is provided with a central bore I '3 within which a shaft or rod I2 slidably engages. The shaft or rod I2 is held against endwise and rotary movement relative to the plug or body II by means of a transversely disposed shear or frangible pin I 4.

The cylindrical member or casing II] has threaded into the lower end thereof a jaw contracting member generally designated as I5. The jaw contracting member I as shown in Figure 4 is formed with a central bore I6 having a diameter sufficient to permit the upper end of the drill rod IT to loosely pass therethrough. The lower end of the bore 16 terminates in a flared or conical guide passage I8, and the bore I6 merges at its upper end into a tapering jaw contracting passage I9.

A cylindrical sleeve 2:: is threaded onto the upper end of the jaw contracting member I 5 and engages within the casing or cylindrical member ID. A plurality of tapered jaw members 2| are disposed within the casing I 0 and are formed with toothed or serrated inner faces 22. Each jaw 2I is fixed to an elongated resilient bar 23 which extends upwardly from the jaw contracting member I5, and each resilient bar 23 is secured at its upper end to a collar 24 having a central opening 25.

The shaft I2 has fixed thereto as by welding or other suitable securing means a collar 26 which when the pin I4 is unbroken abuts against the lower end of the plug II. A spring 21 is disposed about the shaft I2 between the collar 26 and the collar 24 so as to constantly urge collar 24 downwardly and retain the rod gripping or clamping members 2| within the tapered jaw contracting bore I9.

In the event the drill rod I! does not stick within the well or well casing the gripping mem bers 22 will be disposed within the upper end of contracting member I5, and the collar 24 will be disposed in downwardly spaced relation with respect to the lower end of shaft I2 as shown in Figure 8. In the event, however, that the drill rod I1 is firmly stuck within the well or well casing so that it cannot be readily pulled therefrom after being gripped by the gripping or clamping members 2|, the latter can be automatically released from the drill rod I7 as will be hereinafter described. A collar clamping sleeve 28 is loosely mounted on the lower portion of shaft I2 below the collar 26 and is provided with a plurality of lengthwise extending resilient fingers 29 having laterally projecting jaws 30 at their lower ends.

The shaft I2 is formed adjacent the lower end thereof with a reduced diameter stud 3| forming a space 32 slightly above the lower end of shaft I2 so that when the collar clamping members 30 a lengthwise extending slot 34 formed in the sleeve 28.

In the use and operation of fishing tool is initially disposed with the parts arranged as shown in Figure 8. At this time .the collar 24 which is fixed to the upper ends of the spring bars 23 is below the collar clamping sleeve 28 and the lower end of shaft l2. Pin M at this time will hold shaft I2 against rotary and endwise movement relative to the plug H. The tool is lowered over the drill rod ll which wili move the jaws 2| upwardly a short distance until the jaws are able to engage beneath the collar at the upper end portion of the drill rod. When the jaws it pass the drill rod collar the jaws will be moved downwardlyby the spring iii.

If the drill rod I! is not stuck within the well or casing the fishing toolwillreadily remove the drill rod from the well or well casing. In the event, however, the drill rod is stuck sufficiently tight that it cannot be pulled; the fishing tool is released from the rod by striking the upper end of the rod connected with a shaft [2. This impact will cause pin 64 to become sheared, and shaft l2' may then be moved downwardly to the position shown in Figure 1. At this time the collar clamping sleeve 23 will have the jaws 3E3 thereof engaged below the collar 24 so that collar 2 with jaw carrying bars 23 will be gripped to shaft l2. The rod connected with shaft i2 is given further jarring so that casing Ii] may slide downwardly until the lower end of plug H engages the upper side of collar 2% which is fixed to shaft l2. Jaws 2| which are biased outwardly to released position by the resilient bars 23 will then move outwardly to disengaged position with respect to the drill rod ii. The fishing tool being now released from the drill rod may be removed by upward movement.

This tool will provide an effective means in the form of a fishing tool whereby broken drill rods can be pulled from the well or well casing in the event the rods are not too tightly stuck within the well or well casing. In the event the this device the 4 drill rod cannot be readily removed from the well or well casing by the fishing tool hereinbefore described, the tool may be released from the drill rod as hereinbefore described.

What is claimed is:

A drill rod fishing tool comprising a tubular casing, ataperedjaw contracting member carried by the lower end of saidcasing, a plug in the upper end of said casing having a central bore, a plurality of tapered drill rod clamping jaws in said casing, spring means constantly urging said jaws downwardly to clamping position, a shaft having a reduced portion slidable through said bore, a collar fiicd to said shaft below said plug, frangible means carried by said plug and extending transversely through said shaft normally holding said collar against the lower end of said plug, a ring above said jaws, resilient bars fixed between said ring and said jaws biasing said jaws to released-position, a sleeve having a limited slidable connection to said shaft above said reduced portion, inwardly biased resilient clamping fingers having outwardly turned lugs engaging under said ring carried by said sleeve, downward movement of said shaft on breaking of said frangible means juxtaposing said clamping fingers to said reduced portion of said shaft to release the engagement of said lugs from said ring to release said ring for downward movement relative to said shaft, whereby said jaws drop downwardly and said contracting member effects clamping of I said jaws on said rod.

THEODORE M; HUNT. TROY LEE NICHOLS.

References Cited in the file of this patent UNITED STATES PATENTS 

